1. Field of the Invention
The present invention relates to a system for handling edible oils and other fluids and, particularly, to a system for distributing, filtering, storing, recovering and disposing of edible oils or other fluids, often while in a hot condition, used in open-top vat type vessels such as fryers, cookers, and related equipment widely used in commercial or institutional food preparation establishments.
2. General Background
Today's high volume food preparation establishments commonly use commercial cooking vats, the majority of which are deep fat fryers using cooking oil or solid shortening. The cooking oil and/or shortening products are held in many individual containers, usually from 35 pound plastic jugs encased in cardboard cartons, to 50 pound blocks of solid shortening in plastic wrapping enclosed in a cardboard box. The cardboard cartons and cardboard boxes are stored indoors, taking valuable space and creating an extremely volatile situation in the case of fire. They also occupy storage space when empty until they can be put into a dumpster and hauledoff.
The cardboard cartons and/or cardboard boxes are manually carried into the storeroom, stacked and manually transferred to and from the vats where they are manually lifted to waist height or higher to fill the cooking vats. Personnel frequently suffer sprains and back injuries when handling the cardboard cartons and/or cardboard boxes. Additionally, food absorbs oil during the cooking process whereby oil or solid shortening must be continually added to the hot oil or liquified shortening. This is a dangerous process resulting in spattering and splashes, particularly when chunks of solid shortening are dropped in the hot liquid. When 50 pound blocks of solid shortening are used, the blocks must be melted very slowly at a low heat to prevent a grease fire when the vats are filled. However, if a grease fire occurs, automatic fire suppressors flood the vats with chemicals, thereby causing a loss of all the oil or shortening. The cooking station must be shut down and cleaned up causing a loss of revenue.
Adding oil frequently results in spillage loss and creates opportunities for slips and falls next to open vats having oil heated to 340 to 375 degrees. Burns are commonplace in high volume food preparation establishments some of which lead to permanent disfigurement and disability.
When food is cooked, the oil quickly becomes fouled with bits of food, batter, breading seasonings, etc. The particles continue to overcook, becoming burned and scorched, thereby degrading the taste and quality of the food and reducing the useful life of the oil. To avoid this situation, it is desirable to filter out as many of these particles as is practical.
Operations that do not filter must throw away large amounts of oil continuously. However, to filter safely, the hot oil should be allowed to cool down to a safe temperature. Cooling of the oil can take from one to several hours, requiring the fry vat to be off-line whereby no income is produced. Most operations try to get back on line quicker, risking the hazards of drawing off hot splashing oil into low, open containers sitting under foot in busy work areas. Although dangerous, it occurs as a normal part of the business. Furthermore, often late at night, near closing time, an employee picks up hot metal pots or buckets full of scalding oil and stumbles out back on multiple trips through dim lighting to a fat disposal tank to dispose of the hot spent oil. To say the least, this is a hazardous situation that needs improving even more than the oil filtering process which is another risky oil handling process that occurs in several ways.
One of the most commonly used filtering process uses mechanical filters receiving oil from the vat drain spout directly into a large open tub. Typically a filtering screen sits in the bottom of the tub, drawing oil through the screen, up a vertical pipe having a pump and motor mounted atop, and discharges the filtered oil via a short length hose and nozzle back into the vat. Dragging the assembly from vat to vat and the lengthy wait required for the unit to cool down so that the motor, pump, pickup tube, screen and other parts can be disassembled and removed for cleansing before the sediment and debris can be manually scooped from the tub are just some of the disadvantages. Furthermore, there are problems of sanitation and storage of a large, greasy, open tub and bulky mechanical components required for the filtering process. After cleaning the sludge, sediment and residual waste, the oil is manually disposed. The disposed of oil is picked up by scrap oil dealers, some of which charge for the removal service, others may pay a small amount for the disposed spent oil. Once removed, the waste oil is out of mind with little concern for what happens to it. There have been instances, as in one case, where the removal company simply dumped the oil over acres of ground, thereby contaminating ground water and threatening an adjacent aquifer system. It is apparent that a comprehensive overall system is needed to prevent such environmental catastrophes.
Several filtering devices and systems for handling of bulk edible oil have been patented.
U.S. Pat. No. 4,462,915 is directed to an edible oil handling system wherein the unit sits down in the fry vat only as deep as the heat tubes passing at mid-height through the fry vat oil. Since many vats have narrow "deep wells" and/or slanting bottoms, removal and filtering of the oil becomes a major problem. After immersion, the unit must be manually transferred to and from fouled and unfouled oil in each vat and catchment container, potentially a very messy, spill-prone process.
U.S. Pat. No. 4,646,793 is directed to a system for supplying and disposing of oil. The system does not perform flushing or use a pressure dispensing wand for cleaning. The filtering and recirculation capability stores the oil overhead indoors and requires several pumps.
U.S. Pat. No. 5,249,511 is directed to a system with supply, disposal, and filtering capability but does not provide a sanitary draining system to flush away larger pieces of food or clumps of heavy bottom sediment. The system relies on a vacuum to extract chunks of debris from under the vat heating tubes and transfers the debris, unstrained and unfiltered, through an extensive piping and valve network to a large remote processing unit. Cross-contamination remains a possibility from a piping network flooded with fouled oil and food bits. Furthermore, the oil storage unit indoors is a fire hazard.
U.S. Pat. No. 3,369,602 is directed to a edible oil handling system which requires multiple pumps and separating devices and the pump motor to be continuously running. There is no provision for disposing of the spent oil.
U.S. Pat. Nos. 3,707,907, 4,945,893 and 5,179,891 are directed to edible oil handling systems requiring proprietary "built-in" mating components in order to function properly with the vat system.
While each of these efforts addresses various segments of edible oil handling, filtering and disposal, none present a safe and effective comprehensive system for distributing, storing, filtering, disposing and recycling of edible oils or other fluids, while in a hot condition.